Compression spring



July 3, 1962 J. GLASER 3,042,391

COMPRESSION SPRING Filed Sept. 25, 1959 INVENTOR. JERRY GLASER,

A rfomey.

ite tates atent 3, 12,391 Fatented July 3, 1962 ffice This invention relates to a compression spring and has for its object a precision compression spring which will maintain normality of the end thrust with respect to the axis of the spring so as to apply a symmetrical load.

Another object of the invention is a compression spring which will avoid twisting or rotational forces incident to its compression or extension.

Another object of the invention is a compression spring providing a substantially uniform linear spring rate which may be varied within relatively wide limits.

A still further object of the invention is a compression spring in accordance with the preceding objects which will have a low spring rate, Le. a small force will cause a relatively large deflection.

Other objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawings illustrating certain preferred embodiments in which:

FIG. 1 is an isometric view of a compression spring according to the present invention;

FIG. 2 is a fragmentary view similar to FIG. 1 and showing a modified construction.

In the specific embodiment illustrated in FIG. 1 the spring is given the general reference numeral 1 and is of generally tubular construction with opposite end thrust annuli 2 and 3 having a plurality of thrust lugs or extensions 4 thereon. The body portion of the spring is provided with a plurality of parallel discontinuous circumferential slots 5 and with a plurality of circumferentially spaced axially extending slots 6. The axially extending slots 6 divide the body of the tubular spring into three separated sectors generally designated at 7. The slots 5 divide the material in the sectors 7 into a plurality of parallel circumferential elements 8 and the discontinuities in the slots 5 provide the elements 8 with end ties 9 joining alternate opposite ends of the elements 8 with their adjacent counterparts.

The resultant group of parallel elements 8 within each of the sectors 7 are thus, with end ties 9, of substantially zigzag configuration. The extreme elements 8 are connected to their adjacent thrust annuli 2 and 3 by end ties 11 and 12, respectively. As illustrated in FIG. 1 the ties 11 and 12 are formed at the same side of each of the groups of elements 8 in each of the sectors 7.

In the modification of FIG. 2 the end tie 12 has been moved to the opposite side of the group of elements 8 and is here shown at 13. In this construction the end tie 11 remains in the position shown in FIG. 1 so that in the modification of FIG. 2 the group of parallel elements 8 is connected to the end thrust annuli at opposite sides of the group. FiG. 2 illustrates a further modification in the position of the end thrust lug 4 which has now been moved into the position shown at 14 opposite the end tie 13, whereas in FIG. 1 the thrust lugs 4 are shown centrally of the group of parallel spring elements 8.

The tieing of the groups to the end thrust annuli at opposite sides of the group may be used with the thrust lug position of FIG. 1 and conversely the thrust lug position of FIG. 2 may be used with the end tie arrangement of FIG. 1. The versatility of these arrangements contributes to the wide variation in spring characteristics which may be designed into the spring construction to cover varying service requirements.

The spring may be formed from a tube with the slots machined therein or may be stamped from a flat sheet and rolled into its tubular form. Grinding or machining operations may be desirable to insure that the surfaces of the end thrust lugs are normal to the axis of the spring and heat treating of the completed spring for strength may be desirable with a final normalizing grinding operation after heat treatment. Again, these elements of construction and formation are flexible within the desired requirements of spring operation.

While the specific embodiment of the invention illustrated in the drawing is comprised of three sectors 7,

that is, three groups of the spring elements 8, it is obvious that the number of separations is not limited to three and that two or more than three groups of elements may be utilized in the spring design according to performance requirements.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation consistent with the prior art.

What is claimed is:

1. A compression spring of generally tubular construction comprising: spaced annular end members; a plurality of individual axially extending segments circumferentially spaced apart by axial slots and disposed between said annular end members, each of said segments including a plurality of spaced, parallel, circumferentially extending elements connected at alternate ends in a substantially zigzag formation; and means securing said individual segments to said annular end members.

2. A compression spring of generally tubular construction comprising: spaced annular end members; a plurality of individual axially extending segments circumferentially spaced apart by axial slots and disposed between said annular end members, each of said segments including a plurality of spaced, parallel, circumferentially extending elements connected at alternate ends in a substantially zigzag formation; and means securing said individual segments to said annular end members, said means comprising end ties extending from the element adjacent the respective annular end member to said end member.

3. A compression spring of generally tubular construction comprising: spaced annular end members; a plurality of individual axially extending segments circumferentially spaced apart by axial slots and disposed between said annular end members, each of said segments including a plurality of spaced, parallel, circumferentially extending elements connected at alternate ends in a substantially zigzag formation; and means securing said individual segments to said annular end members, said means comprising end ties extending from the element adjacent the respective annular end member to said end member, said end ties being located at the same side of each of the segments.

4. A compression spring of generally tubular construction comprising: spaced annular end members; a plurality of individual axially extending segments circumferentially spaced apart by axial slots and disposed between said annular end members, each of said segments including a plurality of spaced, parallel, circumferentially extending elements connected at alternate ends in a substantially zigzag formation; and means securing said individual segments to said annular end members, said means comprising end ties extending from the element adjacent the respective annular end member to said end member, said end ties being located at opposite sides of each of the segments.

5. A compression spring of generally tubular construction comprising: spaced annular end members; a plurality of individual axially extending segments circumferentially spaced apart by axial slots and disposed between said annular end members, each of said segments including a plurality of spaced, parallel, circumferentially extending elements connected at alternate ends in a substantially zigzag formation; means securing said individual segments to said annular end members, said means comprising end ties extending from the element adjacent the respective annular end member to said end member; and end thrust lugs extending from said annular end members intermediate said end ties.

6. A compression spring of generally tubular construction comprising: spaced annular end members; a plurality of individual axially extending segments circumferentially spaced apart by axial slots and disposed between said 15 annular end members, each of said segments including a plurality of spaced, parallel, circumferentially extending elements connected at alternate ends in a substantially zigzag formation; means securing said individual segments to said annular end members, said means comprising end ties extending from the element adjacent the respective annular end member to said end member; and end thrust lugs extending from said annular end members adjacent said end ties.

References Cited in the file of this patent UNITED STATES PATENTS 993,208 Watson et al. May 23, 1911 1,541,124 Dunham June 9, 1925 FOREIGN PATENTS 1,090,004 France Oct. 13, 1954 

